"This is the first [big league] experience for him, and certainly the speed and all that goes into not only just playing at the Major League level for the first time, but you're in a pennant race," said Farrell. "There have been many extended games where you're into many hours on the field. All these are a first for him. And while he may not recognize how much it taxes the body, it's ongoing.
"These are great learning opportunities. The fact is, we've benefited from his offensive side of things and defense for the majority of the time. But he's going through some things that are not uncommon for young players to go through."
In the coming days and into the postseason, Farrell has left open the possibility of using a defensive replacement for Devers in the late innings. On the current expanded roster, Deven Marrero would fill that role. Eduardo Nunez and Brock Holt could sub Devers late in games in the postseason if Marrero isn't on the playoff roster.
"We certainly wouldn't rule that out," Farrell said. "When he first came to us, that was the loose plan. But then he excelled defensively and tabled that for the time being. But if situations call for it, I wouldn't rule it out."
Devers is confident he will play better defense down the stretch.
"I try my best to play the best defense I can out there, and up until now, I think I've played pretty well," Devers said through interpreter Daveson Perez. "The last five days have been tough. Those are things that happen in the game, but I don't want to make errors. It's not something I want to do while I'm up here. I try not to think about it too much or let it get to me and focus on the next play that comes."
Farrell doesn't see any major technical adjustments that Devers needs to make.
"You know, I think there are times when he's coming off a couple of days rest, we've seen a guy that has had tremendous quickness, very good range at third base," said Farrell. "He's come in on balls. He's made barehanded plays. He's made all the plays you would like to see a third baseman make. We recognize and certainly have witnessed and lived the recent five-game stretch here, but I think this is more the aberration than the norm."
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.